1. Field
The present disclosure is directed to a method and apparatus for mobile communication device measurement reporting. More particularly, the present disclosure is directed to transmitting a measurement report based on the signal strength of a serving cell in a wireless communication system.
2. Introduction
Presently, in telecommunications, a home cell, such as a Closed Subscriber Group (CSG) cell, a hybrid cell, a femtocell, a picocell or other home cell can use a small coverage cellular base station typically designed for use in residential or small business environments. It connects to a service provider network via a wired or wireless backhaul connection. Current designs of femtocells typically support 2 to 4 active mobile phones in a residential setting. A home cell allows service providers to extend service coverage indoors, especially where access would otherwise be limited or unavailable. A home cell can also provide services to the user that may not be available on a conventional macro cell, such as, for example, mobile television services or less expensive calling plan services. The home cell incorporates the functionality of a typical base station but extends it to allow a simpler, self-contained deployment.
For example, home cells, such as CSG cells or hybrid cells, are cells used for deployment in a campus or are individual cells used for deployment in users' homes. The home cells co-exist with macro cells and have a smaller coverage area than macro cells. Unlike macro cells, the home cells are unplanned, in that the operator has much less control over their placement and configuration than with macro cells.
Handover between macro cells, such as in a long term evolution system, is based on receiving measurements from a mobile communication device that indicate that the mobile communication device sees better signal quality from a particular neighbor cell than the serving cell. The network configures an A3 measurement event to receive measurement reports for performing handover. The event is normally configured so that the mobile communication device sends a measurement report indicating that the report was triggered by event A3 when a candidate cell is a certain amount of dB better than the serving cell.
When macro cells and home base stations are deployed on the same carrier, the drivers for handover are different. The home base stations are deployed for hotspot coverage in homes, offices etc. Unfortunately, if a home base station is located close to the macro cell, the macro cell signal strength can be significantly stronger that the home base station signal strength even when the mobile communication device is close to the home base station, such as when the user is in the home. In this case, it can be useful to handover the mobile communication device to the home base station even when the signal conditions at the home base station are unfavorable. This would allow the user to avail of any special services available through the home base station. Furthermore, home base stations are not included in the neighbor cell list. Therefore, cell specific offsets cannot be provided for home base stations. Inclusion of home base stations in the neighbor cell list is considered impractical, because home base stations are uncoordinated deployments, and there can be large numbers of them. Thus, the event A3, as defined above, does not fully enable handover to home base stations. Therefore, there is a need for a measurement reporting configuration that allows for handover to home base stations.